Attenuating Effect of an Extract of Cd-Hyperaccumulator Solanum nigrum on the Growth and Physio-chemical Changes of Datura innoxia Under Cd Stress

Abstract

Purpose The use of plant extracts obtained from plants that are highly tolerant to heavy metal toxicity has been beneficial in improving the growth of plants grown under metal toxicity conditions. A lab experiment was performed to elucidate the alleviating role of foliar applied cadmium (Cd)-hyperaccumulator Solanum nigrum (S. nigrum) extract on Datura innoxia (D. innoxia) plants grown under Cd stress (0, 50, and 100 mg Cd kg-1 soil). Methods Growth parameters, photosynthetic pigment content, osmo-metabolic compounds, reduced glutathione and phytochelatins content, oxidative damage, and lignin content and its related enzyme (cell wall-bound peroxidase, POX) were determined. Results Apart from the foliar application response of S. nigrum leaf extract (SNE) in either Cd exposed or non-Cd exposed plants, growth parameters of D. innoxia plant grown under both Cd concentrations (50 and 100 mg Cd kg-1 soil) in terms of root and shoot fresh, dry weight, length, and leaf area were noticeably diminished by 29 and 51%, 29 and 54%, 35 and 70%, 40 and 53%, 30 and 69%, 40 and 60%, and 11 and 23%, respectively, compared with untreated control plants. Foliar delivered SNE secured the photosynthetic pigment, free amino acids, soluble proteins, and soluble sugar content. Additionally, it lessened the adverse effects of Cd stress on D. innoxia plants by curtailing the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) by 28 and 27%, and 21 and 23%, respectively, compared with the plants subjected to 50 and 100 mg Cd kg-1 only. The findings herein indicated that the plant water extract and their interactions in the investigated Cd rates significantly augmented phenolics, alkaloids, reduced glutathione and phytochelatins content. Cell wall stiffening in D. innoxia indicated that lignin content and POX were significantly higher in plants exposed to 100 mg Cd kg-1 soil displaying increase values of 275 and 300%, respectively, against non-Cd treated control. The magnitude of increment imposed by Cd stress was lessened by using SNE that reflects on adequate cell growth advocated by limited lignification, in terms of lignin content, and downregulated POX activity. Owing to SNE application, root and leaves Cd contents were efficiently reduced reflecting apparent plant liveliness compared with the SNE non-treated Cd-stressed plants. Conclusions The outcomes of this study designate that foliar application of the Cd-hyperaccumulator S. nigrum leaf extract can be counted as an unconventional and innovative approach in the alleviation of Cd stress and can be employed as integrated practice when Cd-contaminated regions were exploited for sustainable agriculture of the multipurpose plants.

Induction of resilience strategies against biochemical deteriorations prompted by severe cadmium stress in sunflower plant when Trichoderma and bacterial inoculation were used as biofertilizers

“…The increment of proteins and free amino acids due to PGPB-inoculated soil may be attributed to the activation of stress proteins that include several antioxidant enzymes ( Lamhamdi et al., 2011 ) witnessed by elevated activity of ROS-metabolizing enzymes under either Cd-stressed or non-stressed plants; thus, stimulating the defense system machinery helped the plant to orchestrate itself from damage up to threshold; in addition, eliciting the expression of low–molecular weight proteins comprised the metal ion homeostasis that is assumed to shoulder role in their detoxification, viz ., ASA, GSH (acting as a substrate of APX and GPX, respectively), and tocopherol ( Patel et al., 2012 ). PPO is related to stress conditions and involves the cell wall cross-linking and lignification process resulting in a reduction in cell wall extensibility, which restricts cell growth, revealing exhausted plant tissues ( Bruce and West, 1989 ; Abeed and Salama, 2022 ). PPO oxidatively breaks up phenolic compounds included in the synthesis of quinines and ROS; thus, the promotion of PPO activity exacerbates oxidative stress.…”

Physiological and Germination Responses of Muskmelon (Cucumis melo L.) Seeds to Varying Osmotic Potentials and Cardinal Temperatures via a Hydrothermal Time Model

“…ROS dismutation catalyzed by SOD produces H 2 O 2 as a reaction product, which is then scavenged by CAT and APX activities. , Under water-limited regimes, the levels of APX and guaiacol peroxide (GPX) were reduced. APX is a crucial antioxidant that scavenges ROS during oxidative stress . APX undergoes the catalysis of H 2 O 2 and converts it to normal water using ascorbate as a donor of electrons.…”

“…APX is a crucial antioxidant that scavenges ROS during oxidative stress. 81 APX undergoes the catalysis of H 2 O 2 and converts it to normal water using ascorbate as a donor of electrons. APX expression is differently regulated in response to environmental stresses as well as during normal plant development and growth.…”

Cd Phytoextraction Potential in Halophyte Salicornia fruticosa: Salinity Impact

“…The high--salt-treated plants (100–200 mM) had much more enzyme activity and less Cd toxicity than the low-salt-treated ones (50 mM), which correlated with enhanced plant growth. PO in the present study showed heterogeneous activities, whereas PO (involved in lignin biosynthesis in the plant cells) activity was activated in response to Cd stress because it prevents the entrance of HMs in plants via lignin production, which acts as a mechanical barrier [ 3 ]. Lignification in the cell wall induced by PO activity may involve the destruction of the photosynthetic apparatus due to aging and senescence, revealing restriction of the growth of stressed Cd-impacted cells, which results in aged leaves.…”

“…Cd is identified as a carcinogenic inducer; it ranks 7th among the top 10 toxicants [ 1 ]. It extensively bioaccumulates in soils and water bodies from inappropriate anthropogenic routes such as fertilizers, pesticide impurities, and the extensive use of ash and irrigation with waste water [ 2 , 3 ]. Cd is not degradable or modifiable; thus, it is greatly persistent and accumulates in the environment [ 2 ].…”